Posted: June 01, 2014
Putting water to work
Small-scale hydropower eyed for electricity, irrigationAllen Best
Gravity being what it is, any water flowing between Colorado’s highest and lowest points, a range of 11,124 feet, has great embedded energy. The question is whether that energy can be throttled and put to use.
The answer, of course, is yes. Early gold-seekers used hydraulic mining to blast apart hillsides. Later, turbines were installed in many dams to produce electricity.
And now come new efforts across Colorado to further yoke the power of falling water. One such example is near Yampa, a town between Vail and Steamboat Springs. The site is just a few miles from where the Bear River takes a sharp turn and becomes the Yampa River. On his ranch, Gary Clyncke decided three years ago to use the 126-foot drop in elevation of his irrigation water to power a new center-pivot irrigation system.
Clyncke’s hydro-mechanical center-pivot doesn't produce electricity. It does, however, preclude the need for stringing up power lines to operate the center-pivot sprinklers. The sprinkling system, in turn, saves water -- which is worth money. The 90 acres were previously irrigated with flood irrigation from ditches spread across the field of timothy, brome and clover several inches thick. Center-pivot irrigation requires just one-sixth the water.
That savings motivated Clyncke to invest in center-pivot. This hydro-mechanical system cost $13,000, of which $6,000 came from the Natural Resources Conservation Service, a federal agency. That left Clyncke a cost of $7,000. Payback on that investment is achieved in three years.
Federal aid is motivation, at least in part, because of concerns about salinity. When large volumes of water are applied to fields in flood irrigation, the water picks up salts that are then returned to creeks and then rivers. It’s a major problem on the Western Slope, where water can be used two times for flood irrigation before it enters Utah. Downstream in California’s Imperial Valley, an important source of food for the nation, some fields have become so salty they have been abandoned.
One of the most saline areas is in the Uncompahgre Valley, where Delta, Montrose and Paonia are located. An ancient sea left salts and the element of selenium in unusually large quantities in the Mancos shale. Both are harmful to endangered fish downstream in the Colorado River. “Anything that you can do that helps with salinity also helps with selenium, and vice versa,” says “Dev” Carey, manager of the Delta Conservation District.
Saving money is a strong argument by itself. Farmers spend an average of $33,000 each year on electricity, more than half of that to power irrigation pumps, according to the Colorado Energy Office. Using hydropower to operate these pumps doesn't work everywhere. Farms near Sterling, for example, tend toward flatness. Still, the state agency estimates Colorado has untapped capacity in pressurized irrigation systems to deliver 30 megawatts in direct production of electricity or avoided electricity. To put that into context, it’s enough electricity for 12,125 homes, says Kurt Johnson, president of the Colorado Small Hydro Association.
More potential exists in irrigation ditches. Not just any irrigation ditch will do. It must have flows of more than 100 cubic feet per second, a relatively large volume. And there must be drops of at least 150 feet. When falls of that steepness occur, various devices are used to contain the force.
One such canal is located east of Montrose, where water from the Gunnison River is diverted through a tunnel that emerges near U.S. Highway 50. From there, the water flows through South Canal toward the head of the Uncompahgre Valley. In 2012, the Delta-Montrose Electric Association completed a project that had been talked about for more than 100 years. The two powerhouses generate electricity equal to what is needed for 3,000 homes.
In nearby Delta County, the state has identified nine sites on irrigation ditches where it would be economical to install small hydro systems, collectively producing 0.8 megawatts. That’s given current prices of electricity. Should electricity prices go up, as they have steadily, more potential would exist near Delta and many other locations.
“If you want to understand the opportunities for hydropower, you just follow the water. It’s as straightforward as that,” says Eric Lane, director of conservation services for the Colorado Department of Agriculture.
Technology is not the game-changer. The basic concept has changed relatively little in 100 years. As early as 1885, just a few years after its founding, Aspen had electrical street lights, said to be the first between the Mississippi and the West Coast, thanks to electrical turbines. In 1962, however, the local turbine was removed, undercut by the slightly lower-cost electricity from the big, new dams of the West and then the big coal-fired power plants.
Concerns about greenhouse gases have partly pushed the new look at small hydro. A major impediment, however, was the federal permitting process. Because of sometimes reckless placement of turbines in creeks and rivers, the Federal Power Administration in 1930 was vested with the responsibility of evaluating impact. If well-intentioned, the multi-year regulation of its successor, the Federal Energy Regulatory Commission, has been burdensome to small hydro projects of five megawatts or less.
“It was unbelievable,” says Bob Rich, the former mayor of Ouray, of the FERC process. The town, which bills itself as Switzerland of America, several years ago decided to reduce its carbon footprint. The town set out to augment its hydroelectric output, using mostly existing pipelines. The new turbine now in place produces enough electricity to power the pumps used to circulate water in the Hot Springs Pool, saving $1,600 a month. Hiring a consultant for the FERC process would have killed the favorable economics. The proposition worked only because Rich, a retired teacher, gave the time to send scores of letters and do the other legwork required by federal and state processes.
To lower this unnecessary hurdle, two congressional representatives from Colorado, liberal-minded Rep. Diane DeGette of Denver and Rep. Scott Tipton of Cortez, who was elected with Tea Party support, sponsored separate bills to provide exemptions for cases like Ouray and the South Canal near Montrose. The new laws were signed by President Barack Obama last August, with exemptions already delivered to projects at Silverton and Orchard City, both on the Western Slope, and more expected. A smaller speed bump in state government was being smoothed by a bill that was moving easily through the Colorado Legislature as of mid-March.
Another significant source of electricity could come from the 17 agriculture-related dams in Colorado with potential for hydropower installations. A document titled “Developing Agriculture Hydropower in Colorado,” estimates 40 megawatts of potential given current electricity prices. Of that, 25 MW are already under development. One of the projects is at Ridgway Reservoir, near the town of the same name. Again, towns eager to gain non-carbon sources are pushing to the front of the line for the eight MW of production, Aspen for winter production and Telluride, possibly, for summer. If electricity prices rise, as they have, other dams will also become candidates for retrofits.
Even in steep-sloped Colorado, small hydro projects won’t provide the full alternative to fossil fuels. Taken together, all the potential projects probably don’t add up to one large coal-fired power plant. But here, there, and over yonder – yes, gravity can be harnessed to good effect.